Lt1115 Ultralow Noise, Low Distortion, Audio Op Amp

Transcript

LT1115 Ultralow Noise, Low Distortion, Audio Op Amp U FEATURES ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT ®1115 is the lowest noise audio operational amplifier available. This ultralow noise performance (0.9nV/√Hz at 1kHz) is combined with high slew rates (>15V/µs) and very low distortion specifications. Voltage Noise: 1.2nV/√Hz Max at 1kHz 0.9nV/√Hz Typ at 1kHz Voltage and Current Noise 100% Tested Gain-Bandwidth Product: 40MHz Min Slew Rate: 10V/µs Min Voltage Gain: 2 Million Min Low THD at 10kHz, AV = –10, RL = 600Ω: 0.002% VO = 7VRMS Low IMD, CCIF Method, AV = +10: 0.002% RL = 600Ω VO = 7VRMS The RIAA circuit shown below using the LT1115 has very low distortion and little deviation from ideal RIAA response (see graph). , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S High Quality Audio Preamplifiers Low Noise Microphone Preamplifiers Very Low Noise Instrumentation Amplifiers Low Noise Frequency Synthesizers Infrared Detector Amplifiers Hydrophone Amplifiers Low Distortion Oscillators ■ ■ ■ ■ ■ ■ ■ U TYPICAL APPLICATIO RIAA Phonograph Preamplifier (40/60db Gain) 18V RIN 47.5k (MM) 100Ω (MC) COM CIN 2 (SELECT PER PHOTO CARTRIDGE) + 7 A1 LT1115 – 4 2mA –18V A2 LT1010CT 1µF 35V 1µF 35V 17.8k 4 5 3 562Ω OUTPUT 470µF 35V RL 25k 0.60000 –18V 210k –18V 0.20000 MEASURED 0.0 COMPUTER SIMULATED –0.2000 –0.4000 –0.8000 15nF 470µF 35V 0.40000 –0.6000 COM + VS = ± 18V RS = 25Ω TA = 25°C 3900pF 330pF 22.6Ω 1.0000 0.80000 18V + V– 1 Measured Deviation from RIAA Response. lnput at 1kHz = 1mVRMS Pre-Emphasized RBOOST 49.9Ω 2 2N4304* ~250Ω SELECT FOR 2mA 499Ω V+ + 100Ω 6 + 3 INPUT 1µF 35V 1µF 35V + + DEVIATION (dB) 18V 210Ω SINGLE POINT BOARD GROUND OPEN—MM CLOSED—MC + 2200µF 16V 82.5k 4.7µF FILM –1.000 3900pF RESISTORS 1% *OR USE 2mA CURRENT SOURCE MM = MOVING MAGNET MC = MOVING COIL NOTE: BYPASS SUPPLIES WITH LOW ESR CAPS OTHER CAPS: HIGH QUALITY FILM 20 100 1k FREQUENCY (Hz) 10k 50k LT1115 • TA02 LT1115 • TA01 1115fa 1 LT1115 W W W AXI U U ABSOLUTE RATI GS (Note 1) Supply Voltage ...................................................... ±22V Differential Input Current (Note 5) ...................... ±25mA Input Voltage ............................ Equal to Supply Voltage Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range ..................... 0°C to 70°C Storage Temperature Range ..................–65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U PACKAGE DESCRIPTIO ORDER PART NUMBER TOP VIEW VOS TRIM 1 –IN 2 – +IN 3 + V– 4 VOS TRIM 7 V+ 8 LT1115CN8 6 OUT OVER5 COMP NC 1 16 NC NC 2 15 NC TRIM 3 LT1115CSW 14 TRIM –IN 4 – 13 V + +IN 5 + 12 OUTPUT V– N PACKAGE 8-LEAD PDIP TJMAX = 115°C, θJA = 130°C/W ORDER PART NUMBER TOP VIEW 6 11 OVERCOMP NC 7 10 NC NC 8 9 NC SW PACKAGE 16-LEAD PLASTIC SO TMAX = 115°C, θJA = 130°C/W LT1115 • POI01 Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS VS = ±18V, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS THD Total Harmonic Distortion at 10kHz IMD Inter-Modulation Distortion (CCIF) Av = –10, VO = 7VRMS, RL = 600 Av = 10, VO = 7VRMS, RL = 600 VOS Input Offset Voltage (Note 2) IOS Input Offset Current VCM = 0V 30 200 nA IB Input Bias Current VCM = 0V ±50 ±380 nA en Input Noise Voltage Density fo = 10Hz fo = 1000Hz, 100% tested 1.0 0.9 1.2 nV/√Hz nV/√Hz DC to 20kHz 120 nVRMS – 136 dB Wideband Noise MIN Input Noise Current Density (Note 3) fo = 10Hz fo = 1000Hz, 100% tested MAX UNITS < 0.002 % < 0.0002 % 50 Corresponding Voltage Level re 0.775V in TYP 4.7 1.2 200 2.2 µV pA/√Hz pA/√Hz Input Resistance Common Mode Differential Mode 250 15 Input Capacitance 5 pF ±15.0 V Input Voltage Range ±13.5 MΩ kΩ 1115fa 2 LT1115 ELECTRICAL CHARACTERISTICS VS = ±18V, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP CMRR Common Mode Rejection Ratio VCM = ±13.5V 104 123 dB PSRR Power Supply Rejection Ratio VS = ±4V to ±19V 104 126 dB AVOL Large-Signal Voltage Gain 2.0 1.5 1.0 20 15 10 V/µV V/µV V/µV VOUT Maximum Output Voltage Swing RL ≥ 2kΩ, Vo = ±14.5V RL ≥ 1kΩ, Vo = ±13V RL ≥ 600Ω, Vo = ±10V No Load RL ≥ 2kΩ RL ≥ 600Ω ±15.5 ±14.5 ±11.0 ±16.5 ±15.5 ±14.5 SR Slew Rate AVCL = –1 10 15 V/µs GBW Gain-Bandwidth Product fo = 20kHz (Note 4) 40 70 MHz Zo Open Loop 0utput Impedance Vo = 0, Io = 0 70 Ω IS Supply Current 8.5 MAX UNITS V V V 11.5 mA The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±18V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN VOS Input Offset Voltage (Note 2) ∆VOS/∆T Average Input Offset Drift IOS Input Offset Current VCM = 0V ● 40 300 nA IB Input Bias Current VCM = 0V ● ±70 ±550 nA ● ±13 ±14.8 V CMRR Common Mode Rejection Ratio VCM = ±13V ● 100 120 dB PSRR Power Supply Rejection Ratio VS = ±4.5V to ±18V ● 100 123 dB AVOL Large-Signal Voltage Gain ● 1.5 1.0 15 10 V/µV V/µV VOUT Maximum Output Voltage Swing RL ≥ 2kΩ, Vo = ±13V RL ≥ 1kΩ, Vo = ±11V No Load RL ≥ 2kΩ RL ≥ 600Ω ● MAX 75 280 0.5 Input Voltage Range IS TYP Supply Current Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Input Offset Voltage measurements are performed by automatic test equipment approximately 0.5 sec after application of power. Note 3: Current noise is defined and measured with balanced source resistors. The resultant voltage noise (after subtracting the resistor noise on an RMS basis) is divided by the sum of the two source resistors to obtain current noise. ● ● ±15 ±13.8 ±10 µV µV/°C V V V ±16.3 ±15.3 ±14.3 9.3 UNITS 13 mA Note 4: Gain-bandwidth product is not tested. It is guaranteed by design and by inference from the slew rate measurement. Note 5: The inputs are protected by back-to-back diodes. Current limiting resistors are not used in order to achieve low noise. If differential input voltage exceeds ±1.8V, the input current should be limited to 25mA. 1115fa 3 LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Wideband Voltage Noise (0.1Hz to Frequency Indicated) Wideband Noise, DC to 20kHz Total Noise vs Matched Source Resistance 10 100 FPO RS TOTAL NOISE DENSITY (nV/√Hz) RMS VOLTAGE NOISE (µV) 0.5µV/DIV VS = ± 18V TA = 25°C 1 0.1 – RS + 10 AT 1kHz AT 10Hz 2 RS NOISE ONLY 1.0 VS = ± 18V TA = 25°C 0.5ms/DIV 0.01 100 1k 100k 10k BANDWIDTH (Hz) 1M 0.1 10M 1 LT1115 • TPC02 3 10 30 100 300 1k 3k 10k MATCHED SOURCE RESISTANCE, RS (Ω) LT1115 • TPC03 THD + Noise vs Frequency (AV = –100) AV = – 10 RL = 600 VIN = 2VP-P (700mVRMS) VOUT = 20VP-P (7VRMS) TA = 25°C VS = ±18V 0.001 0.0005 100 1k FREQUENCY (Hz) 0.1 AV = –100 RL = 600 VIN = 200mVP-P (70mVRMS) VOUT = 20VP-P (7VRMS) TA = 25°C VS = ±18V 0.010 100 LT1115 • TPC04 TOTAL HARMONIC DISTORTION + NOISE (%) TOTAL HARMONIC DISTORTION + NOISE (%) 0.010 AV = 10 RL = 600 VIN = 2VP-P (700mVRMS) VOUT = 20VP-P (7VRMS) TA = 25°C VS = ±18V 0.001 1k FREQUENCY (Hz) 1k FREQUENCY (Hz) 20 20k 20k AV = 100 VIN = 200mVP-P (700VRMS) VOUT = 20mVP-P (7VRMS) TA = 25°C RL = 600 VS = ±18V 0.010 0.001 LT1115 • TPC07 100 1k FREQUENCY (Hz) 1k FREQUENCY (Hz) 20k LT1115 • TPC06 THD + Noise vs Frequency (AV = 1000) 0.1 20 100 LT1115 • TPC05 0.0005 0.0005 100 0.010 THD + Noise vs Frequency (AV = 100) THD + Noise vs Frequency (AV = 10) 20 AV = – 1000 RL = 600 VIN = 20mVP-P (7mVRMS) VOUT = 20VP-P (7VRMS) TA = 25°C VS = ±18V 0.001 0.001 20 20k 0.1 TOTAL HARMONIC DISTORTION + NOISE (%) 20 THD + Noise vs Frequency (AV = –1000) TOTAL HARMONIC DISTORTION + NOISE (%) 0.010 TOTAL HARMONIC DISTORTION + NOISE (%) TOTAL HARMONIC DISTORTION + NOISE (%) THD + Noise vs Frequency (AV = –10) 20k LT1115 • TPC08 0.1 AV = 1000 VIN = 20mVP-P (7mVRMS) VOUT = 20VP-P (7VRMS) TA = 25°C RL = 600 VS = ±18V 0.010 0.001 20 100 1k FREQUENCY (Hz) 20k LT1115 • TPC09 1115fa 4 LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS AV = 10 RL = 600 TA = 25°C VS = ±18V 0.010 0.001 0.1 1 OUTPUT AMPLITUDE (VRMS) 10 100 0.1 0.010 0.001 0.0001 10m 10 SLEW LT1115 • TPC12 Voltage Noise vs Temperature 2.0 VS = ± 18V TA = 25°C 0.1 1 10 TYPICAL 1 1/f CORNER = 250Hz 0.1 10 3 10 30 100 300 1k 3k 10k UNMATCHED SOURCE RESISTANCE, RS (Ω) RMS VOLTAGE NOISE DENSITY (nV/√Hz) CURRENT NOISE DENSITY (pA/√Hz) RS NOISE ONLY 1.0 10 10000 1000 10 100 OVERCOMPENSATION CAPACITOR (pF) Current Noise Spectrum RS AT 1kHz COC FROM PIN 5 TO PIN 6 VS = ±18V TA = 25°C 1 10 100 100 AT 10Hz 100 1 0.1 1 0.1 OUTPUT AMPLITUDE (VRMS) 1000 GWB LT1115 • TPC11 Total Noise vs Unmatched Source Resistance 10 10000 AV = 10 RL = 10k TA = 25°C VS = ±18V LT1115 • TPC10 TOTAL NOISE DENSITY (nV/√Hz) Slew Rate, Gain-Bandwidth-Product vs Overcompensation Capacitor SLEW RATE (V/µs) INTERMODULATION DISTORTION (at 1kHz) (%) 0.1 0.0001 10m CCIF IMD Test (Twin Equal Amplitude Tones at 13 and 14kHz)* GAIN AT 20kHz INTERMODULATION DISTORTION (at 1kHz) (%) CCIF IMD Test (Twin Equal Amplitude Tones at 13 and 14kHz)* VS = ±18V 1.6 1.2 AT 10Hz 0.8 AT 1kHz 0.4 0 1k 100 FREQUENCY (Hz) 10k 0 LT1115 • TPC14 15 30 45 TEMPERATURE (°C) 60 75 LT1115 • TPC15 LT1115 • TPC13 Voltage Noise vs Supply Voltage 1.5 10 1.25 1.0 AT 1kHz 0.75 50 9 VS = ±18V 8 VS = ±15V 40 SHORT-CIRCUIT CURRENT (mA) SINKING SOURCING TA = 25°C SUPPLY CURRENT (mA) RMS VOLTAGE NOISE DENSITY (nV/√Hz) Output Short-Circuit Current vs Time Supply Current vs Temperature 7 VS = ± 5V 6 5 4 3 2 1 0 ±5 ± 10 ± 15 SUPPLY VOLTAGE (V) ±20 30 20 10 0 – 10 – 20 – 30 25°C – 40 0 0.5 VS = ± 18V 25°C 0 15 LT1115 • TPC16 30 45 TEMPERATURE (°C) – 50 60 75 LT1115 • TPC17 2 3 0 1 TIME FROM OUTPUT SHORT TO GROUND (MINUTES) LT1115 • TPC18 *See CCIF Test Note at end of “Typical Performance Characteristics”. 1115fa 5 LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Gain, Phase vs Frequency 60 120 50 50 40 40 100 80 60 40 70 0 60 30 30 GAIN 20 20 10 VS = ±18V TA = 25°C CL = 10pF 0 –20 0.01 0.1 1 10 100 1k 10k 100k 1M 10M 100M FREQUENCY (Hz) LT1115 • TPC19 – 10 10k Voltage Gain vs Load Resistance RL = 2kΩ 100k 1M 10M FREQUENCY (Hz) – 10 100M 1 0 LT1115 • TPC20 –1 OVERSHOOT (% ) COMMON MODE LIMIT (V) REFERRED TO POWER SUPPLY RS 2k + – 50 CL 40 AV = – 1, RS = 2k AV = – 10 RS = 200Ω 30 20 AV = – 100 RS = 20Ω 10 VS = ±18V TA = 25°C 0 10 10 100 1000 CAPACITIVE LOAD, CL (pF) LT1115 • TPC22 Common Mode Rejection Ratio vs Frequency VS = ± 5V –2 –3 VS = ± 18V –4 +4 +3 VS = ± 5V TO ±18V +2 +1 V– 0 10000 15 30 45 TEMPERATURE (°C) LT1115 • TPC23 60 75 LT1115 • TPC24 Power Supply Rejection Ratio vs Frequency 140 ± 20 LT1115 • TPC21 Common Mode Limit Over Temperature 30pF 60 10 ± 10 ± 15 ±5 SUPPLY VOLTAGE (V) V+ 70 1 LOAD RESISTANCE (kΩ) 10 Capacitance Load Handling VS = ±18V TA = 25°C ILMAX = 27mA AT 25°C 1 0.1 RL = 600Ω 0 80 100 Large-Signal Transient Response POWER SUPPLY REJECTION RATIO (dB) 160 120 100 80 60 40 20 0 10 VS = ± 18V TA = 25°C 100 10k 1k 100k FREQUENCY (Hz) 1M 10M LT1115 • TPC25 140 120 5V/DIVISION VOLTAGE GAIN (V/µV) TA = 25°C PHASE 10 VS = ± 18V TA = 25°C RL = 2k 100 VOLTAGE GAIN (V/µV) VOLTAGE GAIN (dB) 140 20 COMMON MODE REJECTION RATIO (dB) Voltage Gain vs Supply Voltage 70 PHASE MARGIN (DEGREES) VOLTAGE GAIN (dB) Voltage Gain vs Frequency 160 NEGATIVE SUPPLY 100 POSITIVE SUPPLY 80 FPO 60 40 20 1µs/DIVISION VS = ±18V TA = 25°C 0 0.1 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) AV = –1 RS = Rf = 2k Cf = 30pF LT1115 • TPC26 1115fa 6 LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Maximum Output vs Frequency (Power Bandwidth*) PEAK-TO-PEAK OUTPUT VOLTAGE (V) 20mV/DIVISION 30 FPO 0.2µs/DIVISION AV = –1, RS = Rf = 2kΩ Cf = 30pF CL = 80pF Closed-Loop Output Impedance 100 VS = ±18V TA = 25°C RL = 2kΩ 25 OUTPUT IMPEDANCE (Ω) Small-Signal Transient Response 20 15 *POWER BANDWIDTH SLEW RATE fP = πEOP 5 f = POWER BANDWIDTH P EP-P = PEAK-TO-PEAK AMPLIFIER 10 0 10k 1 AV = 1000 0.1 AV = 5 0.01 OUTPUT VOLTAGE 1M 100k FREQUENCY (Hz) 10 IO = 1mA VS = ±18V TA = 25°C 10M 0.001 10 100 10k 1k FREQUENCY (Hz) 100k 1M LT1115 • TPC29 LT1115 • TPC30 CCIF Testing FPO Note: The CCIF twin-tone intermodulation test inputs two closely spaced equal amplitude tones to the device under test (DUT). The analyzer then measures the intermodulation distortion (IMD) produced in the DUT by measuring the difference tone equal to the spacing between the tones. The amplitude of the lMD test input is in sinewave peak equivalent terms. As an example, selecting an amplitude of 1.000V will result in the complex IMD signal having the same 2.828V peak-to-peak amplitude that a 1.000V sinewave has. Clipping in a DUT will thus occur at the same input amplitude for THD + N and IMD modes. U W U U APPLICATIO S I FOR ATIO The LT1115 is a very high performance op amp, but not necessarily one which is optimized for universal application. Because of very low voltage noise and the resulting high gain-bandwidth product, the device is most applicable to relatively high gain applications. Thus, while the LT1115 will provide notably superior performance to the 5534 in most applications, the device may require circuit modifications to be used at very low noise gains. The part is not generally applicable for unity gain followers or inverters. In general, it should always be used with good low impedance bypass capacitors on the supplies, low impedance feedback values, and minimal capacitive loading. Ground plane construction is recommended, as is a compact layout. Voltage Noise vs Current Noise The LT1115’s less than 1nV/√Hz voltage noise matches that of the LT1028 and is three times better than the lowest voltage noise heretofore available (on the LT1007/1037). A necessary condition for such low voltage noise is operating the input transistors at nearly 1mA of collector currents, because voltage noise is inversely proportional to the square root of the collector current. Current noise, however, is directly proportional to the square root of the collector current. Consequently, the LT1115’s current noise is significantly higher than on most monolithic op amps. 1115fa 7 LT1115 U W U U APPLICATIO S I FOR ATIO Therefore, to realize truly low noise performance it is important to understand the interaction between voltage noise (en), current noise (in) and resistor noise (rn). Total Noise vs Source Resistance The total input referred noise of an op amp is given by et = [en2 + rn2 + (inReq)2]1/2 where Req is the total equivalent source resistance at the two inputs and rn = √4kTReq = 0.13√Req in nV/√Hz at 25°C As a numerical example, consider the total noise at 1kHz of the gain of 1000 amplifier shown below. 100k 100Ω – The plot also shows that current noise is more dominant at low frequencies, such as 10Hz. This is because resistor noise is flat with frequency, while the 1/f corner of current noise is typically at 250Hz. At 10Hz when Req > 1kΩ, the current noise term will exceed the resistor noise. When the source resistance is unmatched, the Total Noise vs Unmatched Source Resistance plot should be consulted. Note that total noise is lower at source resistances below 1kΩ because the resistor noise contribution is less. When Rs > 1kΩ total noise is not improved, however. This is because bias current cancellation is used to reduce input bias current. The cancellation circuitry injects two correlated current noise components into the two inputs. With matched source resistors the injected current noise creates a common-mode voltage noise and gets rejected by the amplifier. With source resistance in one input only, the cancellation noise is added to the amplifier’s inherent noise. LT1115 100Ω rn = 0.13√200 = 1.84nV/√Hz In summary, the LT1115 is the optimum amplifier for noise performance—provided that the source resistance is kept low. The following table depicts which op amp manufactured by Linear Technology should be used to minimize noise—as the source resistance is increased beyond the LT1115’s level of usefulness. en = 0.85nV/√Hz Best Op Amp for Lowest Total Noise vs Source Resistance + LT1115 • AI01 Req = 100Ω + 100Ω||100k ≈ 200Ω in = 1.0pA/√Hz et = [0.852 + 1.842 + (1.0 x 2.0)2]1/2 = 2.04nV/√Hz output noise = 1000 et = 2.04µV/√Hz At very low source resistance (Req < 40Ω) voltage noise dominates. As Req is increased resistor noise becomes the largest term—as in the example above—and the LT1115’s voltage noise becomes negligible. As Req is further increased, current noise becomes important. At 1kHz, when Req is in excess of 20kΩ, the current noise component is larger than the resistor noise. The Total Noise vs Matched Source Resistance plot in the Typical Performance Characteristics section, illustrates the above calculations. SOURCE RESISTANCE (NOTE 1) 0 to 400Ω 400Ω to 4kΩ 4kΩ to 40kΩ 40kΩ to 500kΩ 500kΩ to 5MΩ > 5M BEST OP AMP AT LOW FREQ (10Hz) WIDEBAND (1kHz) LT1028/1115 LT1007/1037 LT1001* LT1012* LT1012* or LT1055 LT1055 LT1028/1115 LT1028/1115 LT1007/1037 LT1001* LT1012* LT1055 Note 1: Source resistance is defined as matched or unmatched, e.g., RS = 1kΩ means: 1kΩ at each input, or 1kΩ at one input and zero at the other. *These op amps are best utilized in applications requiring less bandwidth than audio. 1115fa 8 LT1115 U TYPICAL APPLICATIO S R1 1k, 0.1% R3 316k, 0.1% 18V + 2 – LT1115 3 + 100 1% OUT 4 –18V R2 1k, 0.1% 4.7µF FILM 6 + 1µF 35V LOW ESR 10k 1% NOTE: MATCH RESISTOR PAIRS R1 = R3 TO ± 0.1% R4 R2 R4 316k, 0.1% LT1115 • TA03 Figure 1. Balanced Transformerless Microphone Preamp THD + Noise vs Frequency (Figure 1) TOTAL HARMONIC DISTORTION + NOISE (%) INPUT RP 30k 1% 1µF 35V LOW ESR 7 1 TA = 25°C RL = 100kΩ VIN = 10mVRMS VOUT = 2.92VRMS RS = 150Ω 0.1 0.010 20 100 1k FREQUENCY (Hz) 20k LT1115 • TA04 1115fa 9 LT1115 U TYPICAL APPLICATIO S 18V 18V 49.9Ω + INPUT R1 100Ω 3 C1 33pF 8 – 4 1 V+ 100Ω 6 IN RL V– 2N4304* R2 909Ω + ~250Ω SELECT FOR 2mA + 33.2k 1% OUTPUT LT1010CT 2mA –18V 1µF 35V 1µF 35V 7 + LT1115 2 + RBOOST 1µF 35V –18V RESISTORS 1% METAL FILM CAPACITORS – BYPASS; LOWER ESR OTHER: POLYESTER OR OTHER 1µF HIGH QUALITY FILM. 35V *OR USE 2mA CURRENT SOURCE. 33.2k 1% 100k 18V 1µF 35V 1µF + 7 – 6 2 LT1097 3 + 4 + –18V OPTIONAL SERVO LOOP LOWERS OFFSET TO < 50µV 100k 1µF 35V 1µF LT1115 • TA05 NOTE 1: USE SINGLE POINT GROUND. NOTE 2: USE ≥ 470µF CAPACITORS AT EACH INCOMING SUPPLY TERMINAL (I.E. AT BOARD EDGE). NOTE 3: FOR BETTER NOISE PERFORMANCE AT SLIGHTLY LESS DRIVE CAPABILITY: R1 = 43Ω, R2 = 392Ω DELETE C1. Figure 2. Low Noise DC Accurate x 10 Buffered Line Amplifier TOTAL HARMONIC DISTORTION + NOISE (%) THD + Noise vs Frequency (Figure 2) 0.010 TA = 25°C VS = ± 18V VIN = 500mVRMS VOUT = 5VRMS RS = 10Ω RL = 600Ω 0.001 0.0001 20 100 1k FREQUENCY (Hz) 20k LT1115 • TA07 1115fa 10 LT1115 U TYPICAL APPLICATIO S 100pF GAIN: 40dB 30dB 24.9Ω 75Ω 475Ω 2.49k 18V 0.01µF 100Ω 2 – + 7 1µF 35V OUTPUT TO RIAA STAGE 1M 6 LT1115 3 INPUT + 7 4 6 + 18V – 18V 100µF 35V 18V 3 + LT1097 100k 2 – 1µF 100V 1µF 100V 1M 4 –18V 100µF RESISTORS 1% METAL FILM 35V CAPACITORS—BYPASS: LOW ESR OTHER: HIGH QUALITY FILM + – 18V + NOTE 1: USE SINGLE POINT GROUNDING TECHNIQUES 1µF 35V LT1115 • TA06 CCIF IMD Test (Twin Tones at 13 and 14kHz) (Figure 3) Noise vs Frequency (Figure 3) 0.1 10µ TA = 25°C VS = ± 18V RL = 100k 0.010 TA = 25°C VS = ±18V INPUT GROUNDED 1µ NOISE (V) INTERMODULATION DISTORTION (AT 1kHz) (IMD) (%) Figure 3. RIAA Moving Coil “Pre-Pre” Amplifier (40/30dB Gain Low Noise Servo’d Amplifier) 100n 0.001 0.0001 0.1 10n 1 OUTPUT AMPLITUDE (VRMS) 10 LT1115 • TA08 20 100 1k FREQUENCY (Hz) 20k NOTE: NOISE AT 1kHz REFERRED TO INPUT ~2nV LT1115 • TA09 1115fa 11 LT1115 U TYPICAL APPLICATIO S 18V 1µF 35V + + 470µF 35V 100pF RIAA NETWORK 2.49k + 1µF 2 3 100Ω + 35V R1 6081Ω 6 LT1115 3 0.01µF 7 + 4.7µF FILM 6 LT1056 4 + MOVING COIL INPUT 7 – 1µF 35V C1 0.1645µF 2 R2 490Ω C2 0.483µF – OUTPUT 499Ω 4 100k 10k 499Ω + 12.1Ω 1µF 35V –18V RESISTORS 1% METAL FILM CAPACITORS—BYPASS: LOW ESR OTHER: HIGH QUALITY FILM NOTE 1: 1kHz GAIN = 53dB NOTE 2: IN RIAA NETWORK VALUES SHOWN ARE MEASURED AND PRODUCE THE “DEVIATION FROM RIAA” GRAPH SHOWN. THE CALCULATED EXACT VALUES ARE: R1-6249Ω C1-0.161µF LT1115 • TA10 R2-504Ω C2-0.47µF 470µF 35V + Figure 4. Moving Coil Passive RIAA Phonograph Pre-Amp Deviation from RIAA Response Input at 1kHz = 232µVRMS Pre-Emphasized (Figure 4) THD + Noise vs Frequency Input at 1kHz = 232µVRMS Pre-Emphasized (Figure 4) VS = ± 18V RL = 100k RS = 10Ω TA = 25°C 0.40000 0.30000 DEVIATION (dB) TOTAL HARMONIC DISTORTION + NOISE (%) 0.50000 0.20000 0.10000 0.0 – 0.1000 – 0.2000 – 0.3000 – 0.4000 – 0.5000 20 100 1k FREQUENCY (Hz) 20k LT1115 • TA11 0.1 VS = ±18V RL = 100k RS = 10Ω TA = 25°C 0.010 0.001 20 1k 100 FREQUENCY (Hz) 20k LT1115 • TA12 1115fa 12 LT1115 U TYPICAL APPLICATIO S 470µF 35V 18V + 2.5k REV. AUDIO 1µF 35V TAPER + + 1N4002 100pF 4.99Ω 2 RED 100Ω 3 YELLOW 7 – + V+ 22Ω 100Ω 6 LT1115 1µF 35V 49.9Ω BOOST IN 2.49k 10Ω LT1010CT BRN OUT 4 OPTIONAL SINGLE-ENDED TO BALANCED OUTPUT TRANSFORMER V– 2N4304** RED 150Ω MICROPHONE INPUT 6.19k BRN 2mA ORANGE JENSEN JE-11-BM BLK + 1µF 35V 470µF 35V + WHT + CASE YEL ~250Ω SELECT FOR 2mA 1µF 35V RESISTORS 1% METAL FILM CAPACITORS—BYPASS: LOW ESR OTHER: HIGH QUALITY FILM NOTE: USE SINGLE POINT GROUND 1N4002 –18V JENSEN JE-16-A/B 18V 7 6 LT1115 • TA13 100k + 1µF 35V 3 JE-16-A/B & JE-11-BM AVAILABLE FROM: JENSEN TRANSFORMERS 10735 BURBANK BLVD. N. HOLLYWOOD, CA 91601 (213) 876-0059 ** OR USE 2mA CURRENT SOURCE 100k LT1097 4 10Ω 2 + 10k * JENSEN NETWORK VALUES—FACTORY SELECTED. – 1µF 1µF 35V + 1µF –18V Figure 5. High Performance Transformer Coupled Microphone Pre-Amp Risetime of High Performance Transformer Coupled Microphone Pre-Amp (Figure 5) 1 Frequency Response (Gain = 20dB) Balanced In/ Balanced Out (Figure 5) 1.0000 VS = ±18V VIN = 0.95VRMS RL = 600Ω RS = 150Ω TA = 25°C 0.1 AMPLITUDE (dB) REFERRED TO 1kHz TOTAL HARMONIC DISTORTION + NOISE (%) RISETIME OF PRE-AMP AV = 20dB VIN = 400mV 2kHz SQUARE WAVE MEASURED AT SINGLEENDED OUTPUT BEFORE TRANSFORMER THD + Noise vs Frequency (Gain = 20dB) Balanced In/ Balanced Out (Figure 5) 0.010 0.0 – 1.000 – 2.000 – 3.000 – 4.000 0.001 0.0005 20 100 1k FREQUENCY (Hz) 20k LT1115 • TA15 – 5.000 10 VS = ±18V VIN = 0.95VRMS RL = 600Ω RS = 150Ω TA = 25°C 100 10k 1k FREQUENCY (Hz) 100k LT1115 • TA16 1115fa 13 LT1115 U TYPICAL APPLICATIO S R1 2k 200Ω 15V + 3 2k 200Ω + 1µF – 6 + 470µF 35V 1µF 35V + 100Ω – 15V RBOOST = 49.9Ω 2 IN 1 4 LT1010 2 3 500Ω (20T) 2.4k 20VP-P OUTPUT 5 3 4 1µF 35V –15V 5.6k –15V + 15V 2 LT1022 4 7 + 7 35V 1µF 35V LT1115 R2 15V C2 0.1µF FILM + 1µF 35V + C1 0.1µF FILM 1µF 35V 4.7k 10pF –15V 10µF + + –15V MOUNT, 1N4148's IN CLOSE PROXIMITY 1k 1 2πRC WHERE R1C1 = R2C2 MEASURED WITH R1 = R2 = 1.5k 120k –15V 470µF 35V 1µF 10k + + 10k 2.5V LT1004's 1.2V f= + 15V 1µF 35V 7 100Ω – VACTEC VTL 5C10 LT1006 + 4 <5ppm DISTORTION AND NOISE AT 1kHz, 20VP-P INTO 100Ω MEASUREMENT LIMITED BY RESOLUTION OF AUDIO PRECISION TEST SYSTEM ALL BYPASS CAPACITORS: LOW ESR FILM CAPACITORS = ASC TYPE 315 LT1115 • TA17 Figure 6. Ultralow THD Oscillator (Sine Wave) (< 5ppm Distortion) 1115fa 14 LT1115 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .065 (1.651) TYP .100 (2.54) BSC .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) 1115fa Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 15 LT1115 U PACKAGE DESCRIPTIO SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .398 – .413 (10.109 – 10.490) NOTE 4 16 N 15 14 13 12 11 10 9 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT 1 .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 2 3 4 5 6 .093 – .104 (2.362 – 2.642) 7 8 .037 – .045 (0.940 – 1.143) 0° – 8° TYP .050 (1.270) BSC NOTE 3 .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) S16 (WIDE) 0502 1115fa 16 Linear Technology Corporation LW/TP 1102 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com  LINEAR TECHNOLOGY CORPORATION 1989